Refinements under way to current near infrared (NIR) spectroscopic techniques will expand the range of non-invasive blood and tissue chemistry measurements. These changes also will provide accurate readings unaffected by skin color or body fat.
"Once complete, this device will allow chemical analysis and diagnosis without removing samples from the patient. It will be useful for monitoring surgery patients, assessing severity of traumatic injury, and evaluating injuries in space," said Dr. Babs Soller, researcher on the National Space Biomedical Research Institute's smart medical systems team.
Patients may now encounter NIR spectroscopy at the doctor's office. The pulse oximeter, used for measuring oxygen saturation, employs a small clip placed on the finger or ear to measure the amount of oxygen carried by the blood, along with pulse rate.
"Light in the near infrared region has slightly longer wavelengths than red light. It is important for medicine because those wavelengths, for the most part, actually pass through skin and to some extent bone, allowing you to get chemical information about tissues and blood," said Soller, a research associate professor of surgery at the University of Massachusetts Medical School.
To refine the technology for more varied measurements, Soller and colleagues are gathering data from patients. Study participants include cancer, cardiac surgery and trauma patients.
"We're measuring hematocrit, tissue pH and tissue oxygenation using our device and standard techniques," she said. "These data will give us the information needed to derive equations to calibrate the new NIR instrument."
The blood and tissue measurements will provide key information, such as whether a patient is anemic and whether there are adequate leve
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Contact: Kathy Major
major@bcm.tmc.edu
713-798-5893
National Space Biomedical Research Institute
1-Oct-2002